Improvement in dbop-tube steam-geneeatoes



@uiten "tutes gutem @ffice JOSEPII NASON, OF NEW YORK, N. YJ, ASSIGNORTO HIMSELF, CHARLES H JAMES, AND FRANK MILLWARD, OF CINCINNATI, OHIO.

Leiters Patent No. 82,239, dated September 15, 1.868.

dT/lgs .tlgrhule numb tu in there tcttrts utent zum milking gaat nf thesame.

TO ALL WI-IOM IT MAY CONCERN:

De it known that I, JOSEPH NASON, of the city and county of New York, inthe State of New York.; have invented certain new and usefulImprovements in Drop-Tube Boilers; and I do hereby declare that thefollowing is a full and exact description thereof.

The object of my invention is to provide more elfectually thanheretofore against any conflict of the ascending and descendingcurrents, at or near the top of the drop-tubes, and to provide fortaking the water into the internal tubes from the spaces between thetops of the main` tubes, where the water is preserved, as far 'aspossible, from any disturbance due to the ebullition'in the main tubes.

I will rst describe what I consider the be'st means of carrying out myinvention, and will afterwards designate, the points which -I believe tobe new.

The accompanying drawings form a part of this specification.

Figure lis a section on a small scale.

Figures 2 and 3 are sections on a scale about half size, showing twoforms of the details.

Figure l shows a third form. i.

The figures show the novel parts, with so much of the other4 parts aslappearsnecessary to show their rela.- tions thereto.

Similar letters of reference indicate like parts in all the gures. Tintsare employed mainly to a'id in distingnishing parts, and do notnecessarily indicate materials.

A is thecrown-shect or Hue-sheet, which extends horizontally over aspace, in which the gaseous matter from the fire circulates, and whichsupports above it a stratum of waterfC, as represented. D are the drop,-tubes, open at theii` upper ends, and elosedlatvtheir lower` ends. Thesetubes are Screwed into the tube-sheet A, so as to form a strong andtight connection therewith.

I employ an internal tube, d, which is open both at. the top and thebottom, and through which wateriis allowed to descend, t`o furnish vacurrent, which may rise as it becomes heated, and becomes filled withparticles of steam, thus inducing a double current, one descending`through the interior tube d, and the other ascending on its exterior,and between it and the main tube D.

This general idea of circulating water in this manner'm drop-tubes hasbeen long known and approved, and my invention relates to details of theconstruction, which remain tobe described.

Referring to iig. 2, the outer tube D is extended upward above thetube-sheet A. by adding-a length, D', which may be made of cast iron.-It is open at both ends, and is, or may be, a plain tube, with theexception lthat there is a bent piece of internal pipe east therewith,as indicated b y d', which, when the top is secured upon the maintube,forms a connection with the internal tube 0l. I

The figures represent several modifications of the details. l

Fig. l shows the general arrangement of this part of the boiler on asmall scale. I do not deem it necessary to represent the other portionsof the boiler, as they may be arranged in any approved manner.

Fig. l represents the top piece Dl as threaded in its interior, andfitting upon male threads upon the top of the main tube D.

Fig. -L represents thetop pi'ece as tting within the top of the maintube D. allows the main tube to be introduced, as usual, through thefurnace or space B, and allows the top piece to be conveniently andpermanently applied before the introduction of the tube to its place inthe tube-sheet A.

. Figures 3 and-5 represent another modification, in which the top pieceis in one with the main tube. In this modification, the internal tube dis fastened to the external tube,- or extended top, by cutting andbending outward a portion of the internal tube, so as to form lips,which connect it with sucient force and tightness. It will be readilyseen that the connection, withrthe internal tube el, of the externaltube D need not be perfectly water-tight. Lu thisvform of the invention,the upper end of the internal'tubed may be closed by This latterarrangement any convenient means, so that the water shall enter solelythroughgthe aperture provided in 'the side ofthe extended top.

I have tested my invention very thoroughly, and withhighly-satisfaittoryresults.- The steam generatedin the drop-tube rises,taking with it a current of water, and pours out in a continuous streamat the open top, while the-internal tube d draws from the space betweenthe tops of the tubes a. current of-water, which is nearly free fromparticles of steam. I take care to' so arrange my tubes in the boilerthat there shall be suicient space between the tubes D for the water tocollect and remain tranquil, and I prefer to so construct the boilerthat there shall be a space of two or three inches between the exteriortubes and the outer shell ofY the boiler, as indicated in iig. 1,- fromwhich a current of water may flow inward through the spaces.

The extended top D', with the connected part d', may be conveniently andcheaply made of cast iron` They may be cast as thin as the metal willflow, they being subject to no strain of any importance. The internaltube a7, is made a little smaller than the lower end of the portion d',and is'simply thrust into its place. The lower end ofthe .interior tubed may rest upon the bottom of the main drop-tube D, the internal tubebeing cut at an angle, as represented, tovallow an amp-le space forA thewater to ow out at the bottom.

Having now fully described my invention, what-I claim as new, and desireto secureby Letters Patent, is

as follows: l

1. I claim the within-described extension of the drop-tube upward abovethe upper surface of the tubesheet A, 'and the provision for allowing acurrent of water to enter through the side of such extension, anddescend through an enclosed passage or tube, d, combined and arrangedsubstantially as and for the purpose herein set forth.

2. I claim, ,in connection with the above, making the extended'top D ina separate piece from the main drop-'tube D, and adapted to serve,relatively to the other parts, substantially in the manner and for thepurposes herein spcied. n

JOSEPH NASON.

Witnesses:

C. C'. LrvrNes, `W; C. DEY.

